The use of tubular devices or conduits is well known in the repair or replacement of damaged or diseased lumens within the body. For example, tubular conduits are used to repair lumens such as in the esophagus and colon areas, and in particular, prostheses are used in the vascular system to repair, buttress or replace a weakened section of the vessel. It is well known in the field of vascular surgery to surgically replace a portion of a vessel with an endoprosthesis, such as a vascular graft. Such replacement procedures, however, generally involve invasive surgery, resulting in extensive recovery and high risk of infection and/or rejection.
More recently, the general trend in vascular surgery has moved toward less invasive techniques for repair of vessels. In order to minimize the recovery period and reduce the risk of infection and/or rejection, procedures have been developed for delivery and implantation of endoprostheses using minimally invasive procedures. Commonly, such procedures include intraluminal delivery involving percutaneous insertion of an endoprosthesis by way of a delivery catheter. Such endoprostheses include grafts which are generally in the form of a tubular lining provided for delivery within a section of a body conduit to treat the complications of atherosclerosis, i.e. arterial occlusion or aneurysms. These less invasive procedures permit delivery and implementation of an endoprosthesis without the need for replacement of a portion of the vessel, and thus eliminate major surgical intervention and the risks associated therewith.
In order to secure a graft in place after delivery, it is common practice to employ a variety of mechanical securement means, for example sutures, staples and the like. Additionally, it is well known to employ a stent in combination with a graft in order to support and secure the graft in place within the body passageway after implantation. Stents are typically radially expandable and/or contractible support members which are positioned within a graft member or other tubular prosthesis. In common usage, after a prosthesis has been properly positioned, the stent is expanded to anchor the prosthesis within the body passageway. Natural cell growth through the wall of the prosthesis can then further anchor the prosthesis in place within the body lumen.
As can be appreciated, such mechanical securement means cannot effectively secure an endoprosthesis such as a graft continuously along the entire length thereof. Such mechanical securement can result in unsecured portions of the graft, thus resulting in gaps between the graft wall and the intraluminal wall of the vessel. Such gaps can result in an increased amount of cell growth necessary to anchor the prosthesis in place. Further, such mechanical securement can result in a bulky structure present within the lumen, which can inhibit normal flow through the lumen, and create a site for occlusion within the vessel.
Moreover, in recent years, polytetrafluoroethylene (PTFE) has become increasingly popular for use in such vascular graft applications due to its non-stick and inert properties. As can be appreciated, however, PTFE is difficult to adhere to vessel walls due to these inert properties.
Accordingly, a need exists for an implantable prosthesis which can be easily delivered to a repair site within a vessel, and can be effectively secured to the internal wall surface of the vessel along the length of the prosthesis to limit the gap between the prosthesis and the vessel wall.